1. Field of the Invention
The invention relates to a tape reel and particularly to a reel for storing magnetic tape such as that used in conjunction with computers.
2. Prior Art
In the past, magnetic tape reels have generally comprised either a metallic hub with attached spaced apart metallic flanges, or an all plastic reel having both a plastic hub and plastic flanges.
More recently, glass flanges have been used with a metal hub to provide the user with the ability to view the tape pack through the flange. Such a product, however, is disadvantageous due to its high production cost and impact strength problems associated with the glass material.
Another commercially available reel is an all metal reel; it requires additional fastening hardware for assembly and has the further disadvantage that the tape pack cannot be viewed through the metal flange unless a window is provided. Windows in the flanges are problematic due to the danger of contamination through such a window. In addition, a metal reel lacks resilience and can bend if it is dropped. Any distortion of the reel will compromise performance of the reel.
An all plastic tape reel is illustrated in Applicant's U.S. Pat. No. 4,088,278 which discloses a tape reel specially designed to resist compressive deformation of the surface upon which the tape is wound. A tape reel of this type is fabricated by means of adhesive bonding or by means of ultrasonic welding. U.S. Pat. No. 4,052,020 discloses a reel with plastic flanges and a hub of somewhat elastic plastic material. The reel is assembled, as shown in FIG. 10, by sonic welding and by a solvent bond. The combination of these assembly expedients, however, creates significant problems associated with the migration of bonding materials to the tape and weakening of the plastic material by the solvent.
Sonic welding is an efficient and economical method of fabricating an all plastic reel but may not provide the holding strength required for a large diameter, high performance reel. Solvent bonding is convenient but can compromise the strength of the plastic materials joined. Excess solvent can stress relieve the plastic materials in the area of the joint and cause the assembly to crack. A combination of these joining techniques, as taught by the prior art, presents the problem of eventual bonding materials contamination of the magnetic tape.
It would therefore be highly advantageous to have an all plastic reel having flanges of high transparency such as in a glass reel, yet which is as economical as a metal reel to produce and which could be assembled without the use of associated fastener hardware such as screws, and which preferably uses adhesive and ultrasonic welding in an effective manner to secure the components to each other and to at the same time assure isolation of the adhesive from contaminating the magnetic tape that will be wound upon the reel.